This is about right. As an older prospect his progression should have been almost identical to (if not faster than Cesar Prieto).
A+ for a couple weeks to a month to shake off the rust.
If he hit just average there (he hit well above average) he should have been promoted to AA.
After being at AA for another month (depending on his performance) he should have been promoted to AAA.
He then should have been at AAA for the remainder of the season unless he was doing great, at which point a callup to the bigs would be warranted (only if he was doing great at AAA).
This isn't a prospect, this is closer to the equivalent of say a Seiya Suzuki than a 18 year old Cuban (which is how they are treating him).
For his skill and age, Colas should have been spending most of the season at AAA if he did well at AA, or AA if it was more of a challenge. The Sox are treating him like he is an 18 year old Cuban thats only played in the DSL which is an absolute joke.